In November 2007, the New York Times published an op-ed entitled, "This is Your Brain on Politics," by Marco Iacoboni et al. Soon thereafter, the Neuroethics & Law Blog featured a guest post by Martha Farah that was critical of the op-ed (for additional blogospheric and other online reactions, see here and here). A few days after the op-ed, the New York Times published a letter from 17 neuroscientists entitled "Politics and the Brain," that criticized the op-ed. I made a few nitpicky comments about the neuroscientist letter here.
In the midst of all of this, I invited UCLA neuroscientist Marco Iacoboni to reply. He deferred initially but has now accepted the offer. His reply is posted below verbatim:
Neuroscience and SocietySome time ago Adam Kolber invited me to post a response to some comments on our op-ed published in the New York Times (“Your brain on politics,” November 11, 2007). I initially declined, because I thought that some of those comments were cases of what Daniel Goleman calls ‘amygdala hi-jack,’ when emotions take over rational and fair thinking, because they contained contradictory statements that can’t possibly go together. For instance, a very short letter to the New York Times, signed by 17 cognitive neuroscientists, says in its penultimate paragraph that our op-ed does not provide ‘sufficient detail’ to ‘evaluate the conclusions.’ Surprisingly, the last sentence of this short letter says that we ‘draw unfounded conclusions’ in our op-ed. These contradictory statements have been already noted by Adam Kolber in this blog.Contradictory statements were also made in a Nature editorial that lamented the ‘absurdity’ of our interpretations and then concluded with “And does anyone need a $3-million scanner to conclude that Hillary needs to work on her support from swing voters?” Did we say absurdities or make trivial statements? It can’t be simultaneously both.I tend to respond to what is worth responding, and frankly those contradictions didn’t inspire a response. A recent article by Michael Shermer on SciAm.com - quoting extensively Russ Poldrack, one of the 17 scientists that signed the letter to the New York Times - made me change my mind. Shermer’s article associates our New York Times op-ed with the concept of brain modularity. (It also associates the op-ed with pseudoscience, phrenology, and even astrology, comments that while are not worth responding, are worth citing here to give you a sense of how our op-ed still stirs quite a bit of emotional reactions.) It is amusing to see my name associated with brain modularity. I support the concept of modularity in the brain as much as Sam Harris and Richard Dawkins support religious beliefs or the Christian evangelic right supports stem cell research, abortion, and gay marriage. There is nothing in the New York Times op-ed “This Is Your Brain on Politics,” that advocates modularity. It is quite surprising to see how Shermer embraces Poldrack’s gross distortions of the assumptions behind the New York Times op-ed. As a publisher of Skeptic, shouldn’t Shermer have a more skeptical attitude?It is unlikely that there are module a la Fodor in the brain. Indeed, not even Fodor probably believes it anymore. However, there is a large peer-reviewed scientific literature that associates mental states with brain structures. It is possible to use such literature to interpret brain activity as ‘probabilistic marker of mental states.’ For instance, there are more than 1,000 peer-reviewed published papers that associate the amygdala with anxiety. There are also some papers that associate the amygdala with happiness. How many? Less than 100 (I did this survey about six months ago, this is why I am giving approximate numbers.) It is irrational to assume that activity in the amygdala can be associated with anxiety or happiness with equal probability.Shermer’s article also quotes Poldrack’s criticism on the practice of ‘reversing the causal inference,’ which is the basis of interpreting brain activity as ‘probabilistic marker of mental states.’ Shermer (and the signatories of the letter to the New York Times) fail to say that ‘reversing the causal inference’ is a common practice in neuroimaging. The beautiful study on the neuroanatomy of belief recently published by Sam Harris and colleagues takes the activity in the insula while subjects were reading statements that they did not believe as suggesting that disbelief invokes disgust. There is nothing in Sam Harris’ study that tells us that subjects were truly disgusted. A recent brain imaging study by John Cacioppo on social isolation interprets activity in the striatum as representing reward processing. There is nothing in Cacioppo’s design that can demonstrate that the activity in the striatum truly represents processing of reward. Ironically, Cacioppo also co-signed Poldrack-led letter to the Times quoted by Shermer. I could probably find examples of ‘reversing the causal inference’ for all the signatories of that letter. Indeed, I would argue that even Poldrack himself exploits some level of reverse inference in his own studies. In a recent paper led by Adam Aron (he also signed the letter to the New York Times) on response inhibition, Aron and colleagues interpret activity in pre-SMA (a frontal lobe area) as reflecting a ‘conflict/detection resolution role.’ While this interpretation is very reasonable, it would be much less reasonable if the brain activity was located in primary visual cortex. Aron and Poldrack would have not interpreted activity in primary visual cortex during a response inhibition paradigm as reflecting a ‘conflict/detection resolution role’ of the primary visual cortex. Anatomical location of brain activity matters, because there is not a single study that can reveal the absolute truth. Incidentally, this notion applies to all science, not just brain imaging. Science is about reproducibility of results. The results from individual experiments must always be compared to a larger corpus of data. As Francis Crick said, “Any theory that can account for all of the facts is wrong, because some of the facts are always wrong.” It is highly unlikely that more than 1,000 scientific papers are wrong (amygdala and anxiety), but it is definitely not inconceivable that less than 100 papers are wrong.Our New York Times op-ed applied this rational probabilistic logic to brain responses in voters watching candidates. By doing so, it also provided a splendid example of how one can do civic education by using scientific constructs and rational thinking for issues that matter to people. Sadly, science has still a marginal role in our public discourse and this is in part due to an ‘ivory tower’ attitude of many scientists that are afraid of mixing the ‘pure science’ of the lab with real life issues. The by-product of this attitude is a society in which basic concepts that emerged from science - for instance, evolution - are challenged with the irrational position that the evolutionary framework ‘can’t explain all data.’I would argue that all neuro-something disciplines (neuro-economics, neuro-ethics, neuro-politics and so on) should rely heavily on the very same assumptions we adopted in our op-ed. This is necessary, if one wants to combine the tools developed and the knowledge acquired by neuroscientists to address issues that are important to our society. I would also argue that it is high time for science in general and neuroscience in particular to have an impact on our society. I have already discussed some of these issues in my response to the 2008 Edge question (www.edge.org) and in my book Mirroring People. You may have noticed that there are no science books on the New York Times 100 Notable Books of the Year 2007 list, no science category in the Economist Books of the Year 2007 and only Oliver Sacks in the New Yorker's list of Books From Our Pages. Why does science have such a marginal role? I think there is more than one reason. First, scientists tend to confine themselves in well-defined, narrow boundaries. By doing so, they marginalize themselves and make it difficult for science to have an impact on our society.Scientists, however, may find new ways to have an impact on our society. For instance, by making some changes in scientific practices. In these days, scientific practices are dominated by the 'hypothesis testing' paradigm. While there is nothing wrong with hypothesis testing, it is wrong to confine all science only to hypothesis testing. This approach precludes the study of complex, real world phenomena, the phenomena that are important to people outside academia. It is time to perform more broad-based descriptive studies on issues that are highly relevant to our society.Another dominant practice in science (definitely in neuroscience, my own field) is to study phenomena from an atemporal perspective. Only the timeless seems to matter to most neuroscientists. Even time itself tends to be studied from this 'platonic ideal' perspective. I guess this approach stems from the general tendency of science to adopt the detached 'view from nowhere,' as Thomas Nagel puts is. If there is one major thing we have learned from modern science, however, is that there is no such thing, there is no 'view from nowhere.' It is time for scientists (especially neuroscientists) to commit to the study of the finite and temporal. The issues that matter 'here and now' are the issues that people relate to.How should we do all this? One way of disseminating the scientific method in our public discourse is to use the tools and approaches of science to investigate issues that are salient to the general public. In neuroscience, we have now powerful tools that let us do this. We can study how people make decisions and form affiliations not from a timeless perspective, but from the perspective of what is salient 'here and now,' for instance the current electoral campaign. These are the kinds of studies that naturally engage the general public. While they read about these studies, people are also likely to learn scientific facts (even the 'atemporal' ones) and to absorb the scientific method and reasoning.Marco Iacoboni, MD PhDAuthor, Mirroring PeopleDirector, Transcranial Magnetic Stimulation LabAhmanson-Lovelace Brain Mapping CenterDavid Geffen School of Medicine at UCLA